From 2e7654d42988fcdbe3fb113bd266f16884861d05 Mon Sep 17 00:00:00 2001
From: Raymond Hill <rhill@raymondhill.net>
Date: Tue, 18 Dec 2018 13:37:01 -0500
Subject: [PATCH] Relax semantic of leading/trailing pipes in filter
 expressions in logger

---
 src/js/logger-ui.js | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/js/logger-ui.js b/src/js/logger-ui.js
index 3c98275f5..009918e2b 100644
--- a/src/js/logger-ui.js
+++ b/src/js/logger-ui.js
@@ -1448,14 +1448,16 @@ const rowFilterer = (function() {
                 if ( hardEnd ) {
                     rawPart = rawPart.slice(0, -1);
                 }
-                if ( rawPart === '' ) { continue; }
                 // https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions
                 reStr = rawPart.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+                // https://github.com/orgs/uBlockOrigin/teams/ublock-issues-volunteers/discussions/51
+                //   Be more flexible when interpreting leading/trailing pipes,
+                //   as leading/trailing pipes are often used in static filters.
                 if ( hardBeg ) {
-                    reStr = '(?:^|\\s)' + reStr;
+                    reStr = reStr !== '' ? '(?:^|\\s|\\|)' + reStr : '\\|';
                 }
                 if ( hardEnd ) {
-                    reStr += '(?:\\s|$)';
+                    reStr += '(?:\\||\\s|$)';
                 }
             }
             reStrs.push(reStr);